Express your answer as a mixed number simplified to lowest terms. $18\dfrac{15}{19}-2\dfrac{3}{19} = {?}$
Separate the whole numbers from the fractional parts: $= {18} + {\dfrac{15}{19}} - {2} - {\dfrac{3}{19}}$ Bring the whole numbers together and the fractions together: $= {18} - {2} + {\dfrac{15}{19}} - {\dfrac{3}{19}}$ Subtract the whole numbers: $=16 + {\dfrac{15}{19}} - {\dfrac{3}{19}}$ Subtract the fractions: $= 16+\dfrac{12}{19}$ Combine the whole and fractional parts into a mixed number: $= 16\dfrac{12}{19}$